数字全息关键技术研究

Study on The Key Techniques of Digital Hologram

数字全息术开辟了全息术的新纪元,但实现数字全息术需解决许多关键技术。本文以CCD和EALCD为数字全息基本器件,从理论上和实验上研究实现数字全息的关键技术,即如何使光学系统满足时间相干度、空间相干度、空间带宽积、光束偏振度、条纹对比度、分辨率条件和物距条件,以达到高精度全息测试;并基于这些条件,设计了数字全息测试系统;应用该系统,实现了高清晰度数字全息再现。基于数字全息信息的数值特点,利用计算机技术,采用了Laplacian算子滤波,提高了干涉条纹的对比度,从而为提高测试精度提供了高对比度的干涉图。

Digital holography has opened up a new era of holography,but the realization of digital holography needs to solve many key technologies. Taking CCD and EALCD as basic digital holographic devices, the key techniques of dig-ital holography are researched theoretically and experimentally. The techniques include how to make optical system meet the requirements of temporal coherency,spacial coherency,space bandwidth product,light polarization degree,the con-trast of fringes, resolution conditions and distance conditions, in order to achieve high precision holographic testing. Based on these conditions,the digital holographic testing system was designed. The high précised digital holographic re-construction was realized by appling this holographic system. Based on the numerical characteristics of the digital holog-raphy, Laplacian operator is adopted for filtering to improve the contrast of fringes and therefor provide high-contrast interference figure for increasing the test accuracy by using computer .